Apparatus and method of automatically creating supplemental segment in two-dimensional drawings, and CAD/CAM system having function of automatically creating supplemental segment in two-dimensional drawings

Abstract

The present invention is directed to an apparatus for and a method of automatically creating a supplemental segment in two-dimensional drawings. Two-dimensional drawing data concerning at least three views depicted based on orthogonal projection is previously stored in a drawing data storage device. Knowledge for recognizing three-dimensional solid model restored on the basis of the two-dimensional drawing data is previously stored in a knowledge storage device. The knowledge stored in the knowledge storage device is applied to the two-dimensional drawing data stored in the drawing data storage device, so that the three-dimensional solid model restored on the basis of the two-dimensional drawing data is recognized. An area where the supplemental segment is to be created is determined in the two-dimensional drawings on the basis of the recognized three-dimensional solid model. At least two end points of the supplemental segment to be created are determined in the determined area. The supplemental segment connecting the determined end points is finally created.

What is claimed is: 
     
       1. An apparatus for automatically creating a supplemental segment in two-dimensional drawings, comprising: drawing data storing means for storing two-dimensional drawing data concerning at least three views depicted based on orthogonal projection;   knowledge storing means for storing knowledge for recognizing a three-dimensional model restored on the basis of said two-dimensional drawing data;   recognizing means for applying the knowledge stored in said knowledge storing means to the two-dimensional drawing data stored in said drawing data storing means, to recognize the three-dimensional model restored on the basis of the two-dimensional drawing data;   supplemental segment area determining means for determining an area where the supplemental segment is to be created in the two-dimensional drawings on the basis of the three-dimensional model recognized by said recognizing means;   end point determining means for determining at least two end points of the supplemental segment to be created in the area determined by said supplemental segment area determining means; and   supplemental segment creating means for creating the supplemental segment connecting the end points determined by said end point determining means.   
     
     
       2. The apparatus according to claim 1, wherein the three-dimensional model recognized by said recognizing means includes a circular cylinder, a circular cone, a sphere, a torus, and a tilted circular cylinder. 
     
     
       3. The apparatus according to claim 1, wherein said supplemental segment includes a straight line segment, a circle, an arc, an ellipse, and an elliptic arc. 
     
     
       4. The apparatus according to claims 1, further comprising: auxiliary knowledge storing means for storing auxiliary knowledge for judging whether or not the supplemental segment should be created between the end points determined by said end points determining means, and   judging means for judging whether or not the supplemental segment should be created on the basis of said auxiliary knowledge,   said supplemental segment creating means creating the supplemental segment when said judging means judges that the supplemental segment should be created.   
     
     
       5. The apparatus according to claim 4, further comprising: said auxiliary knowledge storing means storing a plurality of types of auxiliary knowledge,   drawing data feature extracting means for extracting the features of the two-dimensional drawing data, and   auxiliary knowledge selecting means for selecting a suitable type of auxiliary knowledge out of the plurality of types of auxiliary knowledge stored in said auxiliary knowledge storing means on the basis of said extracted features of the two-dimensional drawing data.   
     
     
       6. The apparatus according to claims 1, further comprising: command inputting means for inputting a command to eliminate an unnecessary supplemental segment out of created supplemental segments or a command to create a supplemental segment lacking for the created supplemental segments, and   eliminating/creating means for eliminating or creating the supplemental segment in the two-dimensional drawing data on the basis of the command inputted by said command inputting means.   
     
     
       7. The apparatus according to claim 4, further comprising: command inputting means for inputting a command to eliminate an unnecessary supplemental segment out of created supplemental segments or a command to create a supplemental segment lacking for the created supplemental segments, and   updating means for updating said auxiliary knowledge on the basis of the command from said command inputting means.   
     
     
       8. The apparatus according to claims 1, wherein said apparatus for automatically creating a supplemental segment in two-dimensional drawings is constituted by a computer system.   
     
     
       9. A method of automatically creating a supplemental segment in two-dimensional drawings, comprising the steps of: previously storing in a drawing data storage device two-dimensional drawing data concerning at least three views depicted based on orthogonal projection;   previously storing in a knowledge storage device knowledge for recognizing a three-dimensional model restored on the basis of said two-dimensional drawing data;   applying the knowledge stored in said knowledge storage device to the two-dimensional drawing data stored in said drawing data storage device, to recognize the three-dimensional model restored on the basis of the two-dimensional drawing data;   determining an area where the supplemental segment is to be created in the two-dimensional drawings on the basis of said recognized three-dimensional model;   determining at least two end points of the supplemental segment to be created in said determined area; and   creating the supplemental segment connecting said determined end points.   
     
     
       10. The method according to claim 9, wherein said recognized three-dimensional model includes a circular cylinder, a circular cone, a sphere, a torus, and a tilted circular cylinder. 
     
     
       11. The method according to claim 9, wherein said supplemental segment comprises a straight line segment, a circle, an arc, an ellipse, and an elliptic arc.   
     
     
       12. The method according to claims 9, further comprising the steps of: previously storing in an auxiliary knowledge storage device auxiliary knowledge for judging whether or not the supplemental segment should be created between said determined end points, and   judging whether or not the supplemental segment should be created on the basis of said auxiliary knowledge, and   creating said supplemental segment when it is judged that the supplemental segment should be created.   
     
     
       13. The method according to claim 12, further comprising the steps of: previously storing in said auxiliary knowledge storage device a plurality of types of auxiliary knowledge, extracting the features of the two-dimensional drawing data, and   selecting a suitable type of auxiliary knowledge out of the plurality of types of auxiliary knowledge stored in said auxiliary knowledge storage device on the basis of said extracted features of the two-dimensional drawing data.   
     
     
       14. The method according to claims 9, further comprising the step of: eliminating or creating, on the basis of a command to eliminate an unnecessary supplemental segment out of created supplemental segments or a command to create a supplemental segment lacking for the created supplemental segments which is issued from the exterior, the supplemental segment in the two-dimensional drawing data.   
     
     
       15. The method according to claim 12, further comprising the step of: updating said auxiliary knowledge on the basis of a command to eliminate an unnecessary supplemental segment out of created supplemental segments or a command to create a supplemental segment lacking for the created supplemental segments which is issued from the exterior.   
     
     
       16. The method according to any one of claims 9, wherein said method of automatically creating a supplemental segment in two-dimensional drawings is carried out by a computer system.   
     
     
       17. A CAD/CAM system having a function of automatically creating a supplemental segment in two-dimensional drawings, comprising: drawing data storing means for storing two-dimensional drawing data concerning three views depicted based on orthogonal projection;   knowledge storing means for storing knowledge for recognizing a three-dimensional model restored on the basis of said two-dimensional drawing data;   recognizing means for applying the knowledge stored in said knowledge storing means to the two-dimensional drawing data stored in said drawing data storing means, to recognize the three-dimensional model restored on the basis of the two-dimensional drawing data;   supplemental segment area determining means for determining an area where the supplemental segment is to be created in the two-dimensional drawings on the basis of the three-dimensional model recognized by said recognizing means;   end point determining means for determining at least two end points of the supplemental segment to be created in the area determined by said supplemental segment area determining means; and   supplemental segment creating means for creating the supplemental segment connecting the end points determined by said end point determining means.   
     
     
       18. An apparatus for automatically creating a supplemental segment for enhancing the understanding of two-dimensional drawings on two-dimensional drawing data representing a three-dimensional model, comprising: means for detecting an area where said supplemental segment appears on said two-dimensional drawing data on the basis of the three-dimensional model; and   means for determining the position where the supplemental segment is provided in the area on said two-dimensional drawing data which is detected by said detecting means and creating data representing the determined supplemental segment.   
     
     
       19. A method of automatically creating a supplemental segment for enhancing the understanding of two-dimensional drawings on two-dimensional drawing data representing a three-dimensional model, comprising the steps of: detecting an area where said supplemental segment appears on said two-dimensional drawing data on the basis of the three-dimensional model; and   determining the position where the supplemental segment is provided in the detected area on said two-dimensional drawing data and creating data representing the determined supplemental segment.   
     
     
       20. An apparatus for automatically creating a supplemental segment for enhancing the understanding of two-dimensional drawings representing a three-dimensional model on the two-dimensional drawings, comprising: means for detecting an area where said supplemental segment appears on said two-dimensional drawings on the basis of the three-dimensional model; and   means for determining the position where the supplemental segment is provided in the area on said two-dimensional drawings which is detected by said detecting means and creating the determined supplemental segment.   
     
     
       21. A method of automatically creating a supplemental segment for enhancing the understanding of two-dimensional drawings representing a three-dimensional model on the two-dimensional drawings, comprising the steps of: detecting an area where said supplemental segment appears on said two-dimensional drawings on the basis of the three-dimensional model; and   determining the position where the supplemental segment is provided in the detected area on said two-dimensional drawings and creating the determined supplemental segment.   
     
     
       22. The apparatus according to claim 20, wherein said supplemental segment includes a boundary line segment and a silhouette line segment.